speedy radar gun sg7

1.I am working on speed detector as my final year project.I am not getting this component from market i.e microwave transistor operating at 2.6ghz(NE 021).can someone plz tell me how can i get this transistor.This transistor is used to send waves of frequency of 2.6ghz and after reflecting from the car they are received from which speed is calculated.

2.Secondly can any one tell me that what is the purpose of 1ss99 schottky diode in speedy radar gun sg7.

i am attaching the manual of speedy radar gun (sg7).